# for循环
address = "北京"
for a in address:
    print(a)

# 字符串格式化
# %
grade = "1"
classes = "高三%s班" % grade
print(classes)

# format
grade_2 = "2"
number = "2"
classes_2 = "高三{}班{}号".format(grade_2, number)
print(classes_2)

# f-string(python3.6以上才支持)
grade_3 = "3"
classes = f"高三{grade_3}班"
print(classes)
